PAGE_LIST = []


class BaseClass(object):
    def __init__(self, list):
        self.page_list = list


class OPT(BaseClass):
    """最佳置换算法"""

    def __init__(self):
        super(OPT, self).__init__()


class FIFO(BaseClass):
    """先进先出"""

    def __init__(self):
        super(OPT, self).__init__()


class LRU(BaseClass):
    """最近最久未使用"""

    def __init__(self):
        super(OPT, self).__init__()
